8 minutes per stop is ridiculous and TOTALLY UNNECESSARY!
I don't have an auxiliary fuel tank. I've done multiple SS1Ks, SS2K Golds, several BBGs, an SS3K Gold, and a BBG 3000 Gold. When route planning, I plan for 20 minutes per stop, starting when I turn the bike OFF and ending when I pull-out of the station. I take off my helmet, jacket, and gloves, walk into the restroom, use it, wash up, fuel up, document the stop, EAT food that I've brought (but not at every stop), get my shit together, and resume the ride. I have even casually eaten at restaurants multiple times on a single ride.
To tell a newbie to do every stop at breakneck speeds is irresponsible; no certificate or other record is going to record your ride as the "fastest" and the IBA states time and again that these aren't races.
The stops are not only to get gas, but to refresh the rider. Walk around. Wash up with cool water. Stay inside a bit if it's really hot or cold outside. HYDRATE! Call a friend. Grab some real food (believe it or not, getting a deli sandwich and some chips can really go a long way to make you feel better). STRETCH OUT!
The more rides I do, the more experience I get and I adjust what I do at these stops and during the ride; I'm always looking for ways to make my stops more efficient WITHOUT feeling like I'm rushed. I plan for 20 minutes but now normally take half that time because I have streamlined how I document the stop and some other things. Sometimes though, I take an additional 10 minutes or more. The point is, I take as much time as needed.
For my last BBG Fools Gold, I rode 1,673 miles in 23h 15m using this method. Had I had an auxiliary fuel tank, I could've shaved even more time off of that, and that tank would have come in really useful when I did the BBG 3,000 Gold as the saved time could've been used for more rest.
The bottom line here is that you should stop whenever you need or want one and take as long as you need. Do not tell yourself you can't stop until the next time you get gas! On the colder days, my bladder likes to remind me it's still working and I frequently have to stop every 100 miles or so for about 500-600 miles. It's annoying, but it beats having to hold it in, especially on bumpy roads.